Sound Insulation in Sandwich Panels
Sound insulation of roof and facade cladding is an important factor that determines the acoustic performance of buildings. The desired parameters and calculation methods for sound insulation of sandwich panels are determined during the design phase. When sound waves hit a surface, some of the wave is reflected, some is absorbed, and the rest is transmitted. These ratios vary depending on the shape of the surface, the sound absorption of the material and the frequency of the sound.
Variation of Sound Transmission Loss Depending on Frequency (dB)
Sound transmission loss of sandwich panels varies depending on frequency. The values of sound transmission losses at different frequencies are given below:
| Frequency (Hz) | 50 mm | 60 mm |
|---|---|---|
| 125 | 7,3 | 8,1 |
| 160 | 9,3 | 22,1 |
| 200 | 11,7 | 14,2 |
| 250 | 8,5 | 14,5 |
| 315 | 11,4 | 13,0 |
| 400 | 12,3 | 13,9 |
| 500 | 13,3 | 13,8 |
| 630 | 14,1 | 14,6 |
| 800 | 14,7 | 15,3 |
| 1000 | 15,9 | 16,0 |
| 1250 | 15,3 | 15,3 |
| 1600 | 11,5 | 13,0 |
| 2000 | 11,8 | 18,3 |
| 2500 | 23,4 | 24,2 |
| 3150 | 29,2 | 29,2 |
| 4000 | 32,4 | 32,5 |
| 5000 | 29,8 | 29,8 |
| 6300 | 32,5 | 32,5 |
| 8000 | 36,9 | 36,9 |
Sound Absorption Coefficient Changes with Frequency (dB)
The sound absorption coefficient indicates how much sound energy a surface absorbs. Below are the sound absorption coefficients at different frequencies:
| Frequency (Hz) | 50 mm | 60 mm |
|---|---|---|
| 315 | 0,08 | 0,14 |
| 400 | 0,11 | 0,21 |
| 500 | 0,22 | 0,25 |
| 630 | 0,20 | 0,25 |
| 800 | 0,05 | 0,06 |
| 1000 | 0,59 | 0,69 |
| 1250 | 0,09 | 0,12 |
| 1600 | 0,11 | 0,12 |
| 2000 | 0,04 | 0,22 |
| 2500 | 0,07 | 0,08 |
| 3150 | 0,18 | 0,20 |
| 4000 | 0,07 | 0,11 |